Active Logic Devices

OneShot Device

OneShot Devices generate an on pulse of a desired duration in response to an off to on transition. Each time a OneShot sees a transition, it restarts, so if the transitions are close enough together, the on pulse can be extended indefinitely. If no transitions occur within duration of a OneShot's on pulse, the Oneshot output will go to the off state and remain off until the next off to on transition.

The OneShot has one input terminal, the "clk" terminal, and one output terminal, the "out" terminal. The "clk" terminal looks for off to on transitions. The "out" terminal changes to on when the "clk" input sees an off to on transition, and it changes to off if there are no more "clk" transitions within its duration. The OneShot "out" terminal has no value when the Device is first created.

OneShot Devices are created by running the OneShot Script with the following parameter:

• duration : the length of time, in seconds, the OneShot "out" terminal will stay in the on state before turning off.

Oscillator Device

Oscillators are useful when timing or sampling.

The Oscillator changes its value between on and off periodically. As it is an active Device, it changes its value without any external stimulation.

The Oscillator has a single output terminal, the "out" terminal. The "out" terminal changes between on and off once each period.

Oscillator Devices are created by running the Oscillator Script with the following parameter:

• period : the period, in seconds, it takes to go from an off value, to an on value and back. The Oscillator will spend 1/2 of the period in the off state and 1/2 of the period in the on state.

Reset Device

The Reset Device is used when starting up a system with stateful Devices that need an initial state. Wiring a Reset Device to the reset input of a register will cause the register to start up in a known state.

The Reset Device begins in the on state, stays there for a given duration, and then goes to the off state and remains there.

The Reset Device has a single terminal, the "out" terminal.

Reset Devices are created by running the Reset Script with the following parameter:

• duration : the length of time, in seconds, the Reset Device will stay in the on state before turning off.